How Roth Conversions Are Taxed in 2026
A Roth conversion is simple in principle: you move money from a pre-tax traditional IRA or 401(k) into a Roth IRA. The converted amount is added to your taxable income in the year of conversion and taxed at ordinary income rates. You pay the tax now; everything that grows in the Roth afterward is tax-free forever.
The 2026 federal brackets — extended through at least 2034 under OBBBA — are 10%, 12%, 22%, 24%, 32%, 35%, and 37%. Most retirees converting during the low-income window between retirement and RMDs pay rates of 10–22%. The 2026 standard deduction is $16,100 for single filers and $32,200 for married filing jointly (add $6,000 per person age 65 or older).
Two effects can make the actual tax cost higher than the bracket rate suggests. First, if you receive Social Security, each dollar of conversion increases your “provisional income” — potentially making more of your SS benefit taxable and raising your effective marginal rate to 40.7% or higher (the tax torpedo). Second, if you’re age 63 or older, a large conversion in 2026 will affect your Medicare premiums in 2028 through the IRMAA two-year lookback. This calculator detects both effects and shows warnings when they apply.
This calculator handles single-year conversions. For multi-year planning — modeling the full conversion ladder, RMD trajectory, IRMAA cap enforcement, and bridge fund depletion — use the Roth Conversion Ladder Planner.
Check the torpedo before converting: If you receive Social Security, each dollar of conversion can make more SS income taxable — pushing your effective marginal rate well above the stated bracket rate. Use the Social Security Tax Torpedo Calculator to see your marginal rate at every income level.
Check IRMAA before your 63rd birthday: Conversions made at age 63 or 64 will affect Medicare premiums at 65. Going $1 over an IRMAA threshold can cost thousands per year. Use the Medicare IRMAA Calculator to see exactly how much headroom you have.
Plan your full withdrawal sequence: The account you draw from determines your MAGI — and therefore your future tax bracket and IRMAA exposure. Use the Withdrawal Order Optimizer to compare Traditional First, Roth First, and Tax-Optimal drawdown strategies.